The objective of this umbrella project is to acquire a detailed understanding of the developmental program that culminates in myelin synthesis. We are particularly interested in obtaining molecular level information about the control of expression of both the human and murine myelin basic protein (MBP) genes. To this end, we have cDNA cloned and sequenced both the human and mouse MBP genes and studied their organization. During the current reporting period, we have focused on the characterization of the promoter and enhancer regions of the murine MBP. We have made plasmid constructions using these cis-acting elements and a reporter gene whose expression is easily measured. The constructions have been introduced into the germ line of mice so that the tissue specificity of these cis-acting elements can be verified in an in vivo animal model.